JP6739882B2 - Safety equipment for large injection molding machines - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device for a large-sized injection molding machine in which a worker needs to enter the mold clamping device for maintenance during maintenance of the mold clamping device such as die replacement.

As is well known, the injection molding machine is composed of a mold clamping device for clamping a mold, an injection device for melting an injection material and injecting it into the mold, and the like. In a mold clamping device of an injection molding machine, there are various maintenance works such as replacement of molds, and such maintenance work is dangerous. Therefore, safety measures are taken in the mold clamping device, the entire mold clamping device is covered with a housing, and a safety door is provided in an opening portion reserved for maintenance work. The safety door can only be opened when the injection molding machine is stopped. Alternatively, the injection molding machine is stopped while the safety door is open. When the safety door is open, the servomotor is not driven because the power of the servomotor is cut off as described in Patent Document 1, for example. That is, each device cannot operate. Therefore, as long as the safety door is opened, the worker can safely perform maintenance on the mold clamping device.

JP, 2014-19144, A

As described above, in the injection molding machine, the mold closing device is provided with the safety door, and the maintenance of the mold closing device must be performed by opening the safety door. It can be said that the safety of the worker is sufficiently ensured because the interlock prevents the servomotor from being driven when the safety door is open. However, there are problems. Specifically, there is a possibility that the safety door may be closed even during maintenance. In the case of an injection molding machine in which the tie bars are widely spaced from each other, for example, when the tie bar spacing exceeds 1200 mm, maintenance of the mold clamping device must be performed by an operator who enters the mold clamping device. Then, the worker completely enters inside the safety door, and the safety door may be closed even when the worker is performing maintenance on the mold clamping device. Particularly in the case of a large-sized injection molding machine, a plurality of workers may enter the mold clamping device, and there is a high possibility that the workers will be left behind. If you try to secure the safety only by the interlock depending on the opened/closed state of the safety door, the safety cannot be secured. Therefore, for a large injection molding machine, in addition to ensuring safety by interlocking by opening and closing a safety door, additional safety measures are required in the standard. As an injection molding machine provided with an additional safety measure, for example, an injection molding machine provided with a safety mat provided with a weight detection sensor inside a safety door is well known. If the worker is standing on the safety mat, the injection molding machine cannot operate because the controller is notified that the worker is inside the safety door. However, since the safety mat is made of a resin material, if the molten resin falls from the injection device or the mold, the safety mat will be damaged. Therefore, it cannot be installed directly below the mold clamping device. That is, even if the safety mat can be provided in a semi-hazardous area such as the vicinity of the mold clamping device, it cannot be provided in a dangerous area such as the inside of the mold clamping device, and safety cannot be completely secured. As a substitute for this, a safety tread may be prepared. However, the safety mat and the safety tread are dangerous because the worker stands on the tie bar, and 100% safety cannot be ensured. There is also a method in which a sensor for detecting the presence or absence of a worker is provided by, for example, emitting a laser in the mold clamping device to detect the laser. However, if there is a blind spot in the mold clamping device, the sensor may not be able to detect the worker, and this cannot be said to be completely safe either. On the other hand, there is also a method of ensuring safety through operation. For example, a padlock is provided on the main breaker or the emergency stop push button so that the main breaker cannot be turned on or the emergency stop push button cannot be released. After confirming that no workers are left in the mold clamping device, manually unlock the padlock. Then, the main breaker is turned on and the injection molding machine can be driven. However, in checking whether or not the worker remains inside the safety door, there may be a case where a confirmation omission occurs or the confirmation is forgotten. Depending on the method of ensuring safety by operation, safety cannot always be ensured.

Therefore, the present invention, in a large-sized injection molding machine, mechanically detects that the worker is left behind even if the safety door is closed while the worker is entering the mold clamping device. It is an object of the present invention to provide a safety device for a large-sized injection molding machine, which reliably ensures safety and prevents the injection molding machine from being driven when safety cannot be ensured.

In order to achieve the above object, the present invention is configured as a safety device including two sets of optical sensors in a large-sized injection molding machine. Each set of optical sensors is composed of a light emitting device that emits a light beam and a light receiving device that receives the light beam. When the light beam is blocked, blocking is detected. The two sets of optical sensors are provided adjacent to each other in the vicinity of the safety door provided in the mold clamping device, and when the worker passes through the safety door, the timing of the cutoff causes the worker to move inside the safety door. Detects whether the vehicle has entered or exited. The controller of the large injection molding machine is configured to count the number of workers who are staying inside the safety door based on the signals from the two sets of optical sensors, and to determine permission to drive the large injection molding machine. .. Further, the safety device is provided with an IC card reader/writer inside the safety door, and is configured to read/write the exit/entry state recorded in the IC card possessed by each worker.

That is, the invention according to claim 1 is designed such that, when maintenance is performed in the mold clamping device, a safety door provided in the mold clamping device is opened and a worker enters into the mold clamping device to carry out. A safety device for a large-sized injection molding machine, wherein the safety device includes two sets of optical sensors and an IC card reader/writer, and the two sets of optical sensors include a light emitter that emits a light beam and a light receiver that receives the light emitter. And a block is configured so that when a light beam is blocked, a block is detected, the two sets are provided adjacent to each other in the vicinity of the safety door, and an operator passes through the safety door. the difference in timing of the blocking at the time of being adapted to workers how exited outside what has entered the inside of the safety door is notified to the controller of the large injection molding machine is detected, the The IC card reader/writer is provided inside the safety door so that the exit/entry state recorded in the IC card carried by each worker can be read and written by the IC card reader/writer. The controller can be switched to any one of three modes of an entry check mode/an exit check mode/a standby mode. When the controller is in a standby mode, the safety sensor is controlled by the two sets of optical sensors. When the worker's entry into the door is detected, the mode is switched to the entry check mode, and the IC card reader/writer checks whether or not the IC card has been read within a predetermined time. If is recorded, it is rewritten to the entry state and switched to the standby mode. If the IC card in the entry state is read by the IC card reader/writer in the standby mode, it is rewritten to the exit state. By switching to the exit check mode, the two sets of optical sensors are used to check whether or not the worker has exited within a predetermined time, and when the exit is detected, the standby mode is switched to. The number of workers staying inside the safety door is counted based on the entry and exit of the safety door, and when the number of workers is zero, the driving of the large-sized injection molding machine is permitted. Is configured as a safety device for a large-sized injection molding machine.

INDUSTRIAL APPLICABILITY As described above, the present invention is a large-scale injection in which a worker enters the mold clamping device by opening a safety door provided in the mold clamping device when performing maintenance in the mold clamping device. It is intended for safety equipment of molding machines. According to the present invention, the safety device includes two sets of optical sensors and an IC card reader/writer . The two sets of optical sensors are composed of a light emitting device that emits a light beam and a light receiving device that receives the light beam. When the light beam is blocked, the blocking is detected. provided adjacent to each other in the vicinity of, the difference in timing of blocking when the worker passes the safety door, the operator is detected whether exited in or external enters the inside of the safety door large injection The controller of the molding machine is notified . Since the detection is performed by the two optical sensors, it is possible to accurately and surely check the entry/exit of the worker. The IC card reader/writer is provided inside the safety door, and the exit/entry state recorded in the IC card carried by each worker is read/written by the IC card reader/writer. The controller can be switched to one of three modes of an entrance check mode/an exit check mode/standby mode. When the controller is in the standby mode, two sets of optical sensors are used to move the inside of the safety door. When the worker's entry is detected, the mode is switched to the entry check mode, and the IC card reader/writer checks whether or not the IC card is read within a predetermined time. If there is a read and the exit state is recorded in the IC card, When the IC card reader/writer reads the IC card in the entry state while it is in the standby mode, it is rewritten to the exit state and switched to the exit check mode. It is configured to check whether or not the worker is leaving by the two sets of optical sensors within a predetermined time, and switch to the standby mode when the leaving is detected . If this is the case a departure from the normal operation occurs, as possible out is possible to determine that all is abnormal. According to the present invention, the controller counts the number of workers who are staying inside the safety door based on the entry and exit of the workers and permits the driving of the large-sized injection molding machine when the number of workers becomes zero. Therefore, the number of workers remaining in the mold clamping device can be reliably and accurately grasped, and the driving of the large-sized injection molding machine can be safely started.

1 is a perspective view showing a part of a mold clamping device of a large-sized injection molding machine according to an embodiment of the present invention including a mold according to an embodiment of the present invention, a safety door, and a safety device according to the present embodiment. is there. It is a front view showing a safety device of a large-sized injection molding machine concerning an embodiment of the invention. 7 is a table showing a relationship in which modes change in accordance with an event that occurs in the controller of the safety device according to the embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described. The large-sized injection molding machine 1 according to the present embodiment, which is shown in FIG. 1 in the vicinity of the mold clamping device 2, is composed of the mold clamping device 2 and an injection device not shown. The mold clamping apparatus 2 according to the present embodiment includes a fixed plate 4, a movable plate 5 that is opened and closed with respect to the fixed plate 4, a mold clamping housing (not shown), a fixed plate 4 and a mold clamping housing. It is composed of four tie bars 7, 7... Connected together and a toggle mechanism. The object of the present invention is a large mold clamping device 2 in which a worker enters the mold clamping device 2 during maintenance, and the mold clamping device 2 according to the present embodiment is also formed large.

The mold clamping device 2 is entirely covered with a casing (not shown) to ensure safety, but the casing is provided with a safety door 9. The safety door 9 is configured to open and close in a sliding manner, and a worker opens the safety door 9 to enter the mold clamping device 2. The large-sized injection molding machine 1 is provided with a controller not shown in the figure, and the controller stops the power supply to the motor when the safety door 9 is open so that the large-sized injection molding machine 1 is not driven. Inside the safety door 9, a safety mat 11 is laid in a predetermined range. The safety mat 11 includes a pressure-sensitive sensor, detects the weight of the worker when there is a worker, and notifies the controller that the worker is inside the safety door 9. Therefore, even if the safety door 9 is closed with the worker left behind inside the safety door 9, the safety mat 11 detects the worker and the controller stops the power supply to the motor. This enhances safety. However, the safety mat 11 is made of resin and will be damaged if the molten resin falls or the like. Therefore, the safety mat 11 cannot be laid directly under the mold clamping device 2, and cannot be detected when the worker is entering the central part of the mold clamping device 2. Although safety treads are prepared as an alternative measure, it has already been explained that safety treads cannot secure 100% safety. Therefore, the large-sized injection molding machine 1 according to the present embodiment ensures substantially complete safety by the safety device 13 according to the present embodiment described below.

The safety device 13 according to the present embodiment includes two sets of optical sensors, that is, first and second sets of optical sensors 14 and 15, an IC card reader/writer 17, and a controller of the large injection molding machine 1. There is. The first and second sets of optical sensors 14 and 15 may be intended for light beams of other wavelengths, but in the present embodiment, each is composed of a light emitter that emits infrared light and a light receiver that receives this infrared light. , When infrared rays are blocked, they are detected. Note that FIGS. 1 and 2 show only the light receiver. As shown in FIGS. 1 and 2, the first and second sets of optical sensors 14 and 15 are provided in the vicinity of the safety door 9 and adjacent to each other with a slight horizontal shift. Because of such slight offsets, when a worker enters inside through the safety door 9, it is first detected by the first set of optical sensors 14 by the passage of the worker, and immediately thereafter the second set. Is detected by the optical sensor 15. On the contrary, when the worker exits the safety door 9 outside, it will be detected first by the second set of optical sensors 15 and immediately thereafter by the first set of optical sensors 14. That is, the first and second sets of optical sensors 14 and 15 detect whether the worker is entering the safety door 9 or leaving the safety door 9 when passing through the safety door 9. You can

The IC card reader/writer 17 is a device that reads and writes information about an IC card carried by each worker. The IC card reader/writer 17 is provided horizontally away from the first and second sets of optical sensors 14 and 15. Specifically, it is provided near the mold clamping device 2. Therefore, when the worker enters the safety door 9 through the safety door 9, the IC card is read by the IC card reader/writer 17 after the entry is detected by the first and second sets of optical sensors 14 and 15. Will be Both the first and second sets of optical sensors 14 and 15 and the IC card reader/writer 17 are connected to the controller of the large-sized injection molding machine 1.

The safety device 13 according to the present embodiment counts the number of workers entering and exiting the safety door 9 so that no worker is left in the safety door 9 before driving the large-sized injection molding machine 1. It is possible to reliably detect this. The controller can be switched to three modes to check the entry and exit of workers. Normally, the standby mode M0 is set, and when the worker enters the safety door 9, the mode is switched to the entry check mode M1, and the first and second sets of the optical sensors 14 and 15 and the IC card reader/writer 17 are used. Check the signal to check if the worker is entering normally. Then, when the worker exits from the safety door 9, the exit check mode M2 is switched to, and the operator confirms the signals from the first and second sets of optical sensors 14 and 15 and the IC card reader/writer 17 to check that the worker is normal. It is designed to check if you are leaving.

With reference to the table of FIG. 3, a process when the worker enters the safety door 9 and when the worker leaves the safety door 9 will be described. This table is a summary of the contents processed by the controller by the events E1 to E5 that occur when the controller is in the predetermined modes M0 to M2 and the mode switching, and can also be called a mode transition table. .. When the large-sized injection molding machine 1 is stopped for the first time, the safety door 9 is closed and there is no worker in the safety door 9. At this time, the controller is in the standby mode M0. Each worker owns his or her own IC card, and the "exit status" is recorded in the IC card. When the worker enters the safety door 9 by opening the safety door 9, the worker's entry is detected by the first and second sets of optical sensors 14 and 15 (event E1). Then, the controller switches the mode to the entry check mode M1. The worker causes the IC card reader/writer 17 to read the IC card within a predetermined time after entering the safety door 9. That is, the controller obtains the information of the IC card within a predetermined time from the event E1. When the controller confirms that the "exit state" is recorded in the IC card (event E3), it is determined to be normal and the IC card reader/writer 17 rewrites the information of the IC card to the "entry state". .. Then, the mode is switched to the standby mode M0. The controller counts up the number of workers in the safety door 9. A plurality of workers can enter the safety door 9 by the same procedure, and the controller can count the exact number of workers who have entered.

When the worker tries to leave, the controller is in the standby mode M0. First, the worker causes the IC card reader/writer 17 to read the IC card he has. The "entry state" should be written in the IC card of the worker who has entered, and this is read (event E4). The controller writes the "withdrawal state" to the IC card by the IC card writer 17, and switches to the withdrawal check mode M2. The worker exits the safety door 9 within a predetermined time. Then, the leaving of the worker is detected by the first and second sets of optical sensors 14 and 15 within a predetermined time (event E5). The controller switches the mode to the standby mode M0 when the worker exits normally, and reduces the number of workers remaining in the safety door 9. When all the workers leave the safety door 9 in the same manner, the number of workers remaining in the safety door 9 becomes zero, so the controller permits the driving of the large-sized injection molding machine 1.

The table of FIG. 3 also describes cases where it is determined that an abnormality has occurred in the entry and exit of a worker. There are two events that cause an error when in the standby mode M0. Specifically, when the IC card reader/writer 17 reads the IC card and reads the "exit state" (event E3), the first and second sets of optical sensors 14 and 15 detect the exit ( Error occurs when event E5) occurs. The former event occurs when the operator is inside the safety door 9 but the "exit state" is recorded in the IC card instead of the "entry state". The latter event occurs when the worker tries to leave without reading the IC card into the IC card reader/writer 17. There are four events that cause an error when in the entry check mode M1. First, an error occurs when the entry of a worker is detected by the first and second sets of optical sensors 14 and 15 (event E1). This is because the next worker is about to enter even though the other workers' entry checks have not been completed. Next, if the IC card is not read within a predetermined time from the detection of entry by the first and second sets of optical sensors 14 and 15 (event E2), an error occurs. This is because the workers did not follow the proper procedure for entry. Then, when the "entry state" is read in the IC card (event E4), an error occurs. This is because the “exit state” should be recorded on the IC card possessed by the worker who is going to enter. An error also occurs when the worker's exit (event E5) is detected by the first and second sets of optical sensors 14 and 15. There are four events that cause an error when in the exit mode M2. First, an error occurs when the entry of a worker by the first and second sets of optical sensors 14 and 15 is detected (event E1). This is because another worker is trying to enter while the worker is leaving. Next, an error occurs when the IC card is read and is in the "exit state" (event E3). This is because another worker is trying to enter while checking the exit of the worker. If the "entry state" is read from the IC card (event E4), it is an error because another worker is about to leave during the exit check. Further, when the worker does not detect the withdrawal in the first and second sets of optical sensors 14 and 15 within a predetermined time after reading/writing the IC card at the time of leaving (event E5), this is also determined to be an error. When such an error is detected in the large injection molding machine 1, the controller prohibits the driving of the large injection molding machine 1. The prohibition should continue until the error condition is cleared. The administrator confirms that there are no people in the mold board, determines that the machine is in a safe state, and then performs error elimination processing.

1 Large injection molding machine 2 Clamping device 4 Fixed plate 5 Movable plate 7 Tie bar 9 Safety door 13 Safety device 14, 15 1st and 2nd sets of optical sensors 17 IC card reader/writer

Claims (1)

A safety device for a large injection molding machine, wherein a worker enters into the mold clamping device by opening a safety door provided in the mold clamping device when performing maintenance in the mold clamping device. ,
The safety device includes two sets of optical sensors and an IC card reader/writer ,
The two sets of optical sensors are made up of a light emitting device that emits a light beam and a light receiving device that receives the light beam, and when the light beam is blocked, the blocking is detected. provided adjacent to each other in the vicinity of the door, the difference in timing of blocking when the worker passes through the safety door, or workers that exited outside what has entered the inside of the safety door is detected is adapted to be notified to the controller of the large injection molding machine Te,
The IC card reader/writer is provided inside the safety door so that the exit/entry state recorded in the IC card carried by each worker can be read and written by the IC card reader/writer. Has become
The controller can be switched to one of three modes of an entry check mode/an exit check mode/a standby mode,
In the standby mode, if the two sets of optical sensors detect the entry of the worker into the inside of the safety door, the mode is switched to the entry check mode, and the IC card reader/writer ICs within a predetermined time. Check if the card is read, and if there is a read and the exit status is recorded in the IC card, rewrite it to the entry status and switch to the standby mode,
When the IC card reader/writer reads the IC card in the entering state in the standby mode, the IC card is rewritten into the exiting state and switched to the exit checking mode, and the two sets of optical sensors are used within a predetermined time. Check whether there is an exit of the worker, and switch to the standby mode when the exit is detected,
The controller counts the number of workers staying inside the safety door based on the entry and exit of the workers and permits the driving of the large-sized injection molding machine when the number of workers becomes zero. Safety device for large injection molding machines, which is characterized by

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